BANGALORE: A series of forwards on WhatsApp gave police a crucial tipoff, leading to the arrest of two men who had on Tuesday morning attacked a security guard inside an ATM kiosk in Kammanahalli.

Using Smartphone technology to their advantage, city police stitched up the case with the arrest of Thangya Su, 20, and Ausang Thang, 19, natives of Aizawl district of Mizoram, within 24 hours.

The two men had barged into the Corporation Bank ATM and stabbed the security guard Murugan, 38, on his arms and neck. When he raised an alarm, they fled, leaving the ATM machines untouched.

Police got to work, retrieving CCTV footage clearly showing the faces of the two men. And the hunt began. Teams fanned out across the city, visiting hotels, spas and other businesses where people from the northeast community are usually employed; however, the search wasn't fruitful.

"The kitchen knife was crucial in the investigation. It gave us hunch that these two men were working in some fast food chain or hotel in the city. So we sent these photographs to all the hotels and restaurants we knew, that employed people from the north-east," PS Harsha, deputy commissioner of police, east.

According to DCP PS Harsha, photographs of the men were sent to at least 1,000 restaurants and hotels either physically or digitally.

Throughout Tuesday, members of the community shared the pictures on WhatsApp, until finally, the strategy hit home. The pictures reached a hotelier in Jayanagar, who paid little attention to them until Tuesday evening, when the men walked into his hotel, looking for jobs. He reached for his phone and tapped on the image, and aha! the picture revealed the truth, in all its megapixel clarity.

He knew he had to act fast. He asked them to wait in a room in the hotel, and quickly rang up the cops. Investigating officials are keeping the identity of the hotelier a secret.

During interrogation, the young men said they had come to Bangalore a year ago and were between jobs. They admitted they had set out to rob an ATM after one of their friends gave them the idea on making a fast buck. Around 1am Tuesday, they located a kiosk where the security guard was asleep and attacked him with a kitchen knife.